The present invention generally relates to a governor mechanism for controlling the rotational speed of a rotary device by a centrifugally operated valve means adapted to vary flow of pressurized fluid passing through the governor mechanism. Representation of prior art relating to this general type of mechanism include U.S. Pat. Nos. 444,938; 3,733,143; 4,087,198; 4,776,752; 5,496,173; and 5,567,154.